On Alibaba.com, you can find aquarium heaters that switch on the floating fish and keeping them warm for a long time. They also need to use a aquarium cooler or switch to electric fish tank heaters, on the other hand, they can be used in a variety of situations as they are more easy to maintain.
You can also find small fish tank heaters in a variety of colors and sizes, as well as ultra-low volume fish tank heaters and mini fish tank heaters.